avionic design with actual uboot and tooling

submodule of avionic design uboot bootloader and with included tools to
get you started , read readme.md and readme-tk1-loader.md

u-boot/arch/arm/include/asm/arch-tegra/funcmux.h

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2010-2012, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0
+ */
+
+/* Tegra high-level function multiplexing */
+
+#ifndef _TEGRA_FUNCMUX_H_
+#define _TEGRA_FUNCMUX_H_
+
+/**
+ * Select a config for a particular peripheral.
+ *
+ * Each peripheral can operate through a number of configurations,
+ * which are sets of pins that it uses to bring out its signals.
+ * The basic config is 0, and higher numbers indicate different
+ * pinmux settings to bring the peripheral out on other pins,
+ *
+ * This function also disables tristate for the function's pins,
+ * so that they operate in normal mode.
+ *
+ * @param id		Peripheral id
+ * @param config	Configuration to use (FUNCMUX_...), 0 for default
+ * @return 0 if ok, -1 on error (e.g. incorrect id or config)
+ */
+int funcmux_select(enum periph_id id, int config);
+
+#endif	/* _TEGRA_FUNCMUX_H_ */